A computer-based quantitative measurement system for the care of critically-ill patients is being extended and evaluated. Improved methods are being developed for providing accurate, up-to-date quantitative information about the physiological status of these patients. Present emphasis is on evaluation of the status of heart, lungs and circulation. The work includes studies to determine which measurements are most useful, how to use the measurements most effectively to improve the delivery of health care, and how to make these methods available to medical users outside the central academic community.